We propose the purchase of a ThermoFinnigan LTQ Linear Ion Trap Mass Spectrometer to place in an existing Ophthalmology Proteomics and Mass Spectrometry Core. This instrument is required because the LCQ Classic ion trap now used in the core no longer fulfills the needs of the on-going projects that require an instrument of greater sensitivity and rate of data acquisition. [unreadable] [unreadable] The new instrument will support the on-going research of both Ophthalmology Core sponsored projects, and a number of collaborative projects throughout Oregon Health & Science University. The instrument will be exclusively used for nano-electrospray ionization analysis of peptide digests to generate tandem mass spectral data for protein identification. An existing Agilent capillary liquid chromatography system will be used with the instrument to perform automated analysis in a high throughput environment. The current LCQ classic will be dedicated for use with an atmospheric pressure ionization MALDI source for analysis of simple digests from electrophoresis gels. Dedicating each instrument for either electrospray or MALDI analysis will greatly increase the efficiency of the core and increase productivity. [unreadable] [unreadable] The increased sensitivity and scan rates of the proposed linear trap will be used for complex peptide digests derived from protein/protein interaction studies and shotgun identification and quantification of proteins from tissue homogenates and body fluids. The proposed experiments using multidimensional chromatography are feasible because the core employs two full time bioinformatics specialists and a laboratory associate currently performing these types of experiments, and possessing a suite of software tools and hardware to handle the large data sets. [unreadable] [unreadable] This state-of-the-art instrument will be used in 11 diverse multi-disciplinary projects that will study the molecular causes of: cataract, glaucoma, uveitis, retinitis, corneal injury, cystic fibrosis, nephrotic syndrome, central nervous system dysfunction following exposure to toxins, suppression of apotosis, and glioblastomas. An additional use will be to study the composition of proteins in human saliva to test the usefulness of this fluid to detect biomarkers for disease. [unreadable] [unreadable]